The present invention relates to the field of disposable medicament packages, and more particularly to field of child resistant packages for individual, relatively small oblong medicaments, such as capsules or caplets.
In the past several years, great attention has been directed towards the provision of medicament packaging which is not only child-resistant, but which also provides clear visual evidence of tampering. The provision of suitable child-resistant, tamper-resistant packages is complicated somewhat by the fact that many medicaments are intended for use by elderly, arthritic or infirm users who may not possess the dexterity or strength which is required to readily access the medicaments in tamper or child resistant packages.
Over the years, a wide variety of disposable plastic packages have been suggested which are accessible through a variety of folding, stripping, rupturing, peeling and/or tearing procedures. These packages have typically been formed of transparent top layers which are sealed or otherwise bonded to backing layers in a manner which provides a cavity, pouch or "blister" in which the medicament is disposed. The top and backing layers may be formed of flexible packaging materials, rigid thermoformable plastic materials, foil, paper, or laminates, or combinations thereof. Medicament cavities formed between such layers may be accessed by tearing into them from an edge of the package, which tearing may or may not be facilitated through the provision of a starting notch or slit. Alternatively, these cavities may be accessed by stripping a backing layer from the package to expose the cavity, or to expose a push-through underlayer. These and other access methods may require additional folding, tearing, or stripping to gain medicament access. Furthermore, the packages may be provided individually, or as part of a strip, matrix or array of packages joined by tear-apart perforations.
Tear-open packages of the above described types generally exhibit centered medicament cavities having uniform sealed marginal regions around the peripheries thereof. When the medicament is a pill, these cavities generally comprise generally circular pouches, such as those illustrated in U.S. Pat. Nos. 2,069,333 (Salfisberg); 2,796,9S2 (Volckening); 2,35S,246 (Nicolle) or 3,809,220 (Arcudi); or circular blisters such as U.S. Pat. Nos. 3,456,784 (Sarago) or 4,398,635 (Hirt). Generally rectangular pouches, such as those shown in U.S. Pat. Nos. 3,650,461 (Hutchenson) or 3,276,669 (Vilutis); and substantially square thermoformed cavities such as that shown in U.S. Pat. Nos. 4,091,930 (Buchner et al) are also known. When the medicament is a powder or liquid, other cavity configurations, such as the generally triangular pouch of U.S. Pat. No. 2,103,389 (Salfisberg) or the pleated pouch of U.S. Pat. No. 2,895,606 (Hoag) are also known. See also British specification 577,151 (McGeorge).
Notwithstanding the disclosures of the above-identified patents, tear-opening packages have lost favor in certain applications to blister packages which do not require tearing in order to gain package access. Such packages include stripable, rupturable and/or "peel and push" packages. In stripable packages one or more layers of a multilayer backing laminate must be peeled away from the underside of a blister before the pill or other medicament may be accessed. For examples of stripable packages, see U.S. Pat. Nos. 3,603,453; 3,380,518; 2,834,456; 2,760,630; and 2,530,127. In rupturable packages the pill is generally pushed through a layer of the backing to provide medicament access. See for example, U.S. Pat. Nos. 3,759,371; 3,689,458; 3,494,322; 3,472,367; 3,387,699; 3,331,495; 3,324,995 and 3,276,573. In U.S. Pat. Nos. 3,809,221; 3,899,080; 3,327,843; 3,504,788; 3,429,426 and 2,968,391, and in Reissue 29,705, a combination of opening operations are required. See also U.S. Pat. No. 4,196,809. While packages requiring peeling, folding, stripping, and/or rupturing operations have achieved considerable success in the field, many users do not have the requisite fine motor coordination to easily gain access to such packages. Furthermore, the filling and sealing of such packages may require great care to ensure that the backing materials are sufficiently sealed to the blister layer as to afford substantial child and/or tamper resistance without oversealing those layers to effectively preclude the intended stripping away of one of those layers by the end user.
Many of the above-described packaging problems are aggravated as the size of the medicament to be packaged decreases. Nonetheless, from the standpoint of ease of swallowing, smaller medicaments are generally preferred. Such medicaments include recently developed "caplets" which are oblong tablets of a size equal to or slightly smaller than conventional capsules. In packaging such small medicaments it is not enough to simply consider the characteristics of the package during the initial stages of opening. One must also consider the configuration of the package during the final stages of opening and in its completely opened form, to determine whether the medicament will be retained in or "thrown" from the package, and, if retained, whether it will be sufficiently accessible to permit an arthritic or infirm user to gain reasonable access thereto. Accordingly, while many foldable, stripable, rupturable, and/or tearable packages have been suggested, there remains a need for a low-cost child-resistant, tamper-resistant, blister package for use with relatively small, oblong medicaments, such as caplets.